The Design of Digital Multimeter Automatic Calibration System and Application of PID Algorithm

A digital multimeter automatic calibration system is developed by modifying the traditional multifunctional calibrator, designing the controller and application program. PID closed-loop feedback control algorithm is used to slove the problem of low accuracy of digital multimeter calibration with a small range of 200mV. The test results show that the system has good measurement stability and can realize automatic calibration of digital multimeter.